JP2000273765A - Sizing agent for fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a sizing agent which is used for fibers, gives a good weaving property to the fibers, and has excellent biodegradability, by adding an alkali metal to a specific vinyl alcohol-based polymer. SOLUTION: This sizing agent for fibers is preferably obtained by adding 0.0003-1 pt.wt. (converted into sodium metal) of an alkali metal to 100 pts.wt. of a polyvinyl alcohol-based polymer. The polyvinyl alcohol-based polymer has an ethylene unit content of 2-19 mol.%, a viscosity-average polymerization degree of 200-3,000, a total carboxylic acid and lactone ring content of 0.02-0.40 mol.%, preferably a content satisfying the formula: -1.94×10-5×P+0.44<= content <=-1.39×10-4×P+0.42 (P is a viscosity-average polymerization degree), a 1,2-glycol bond content of 1.2-2.0 mol.%, and the central hydroxyl group mol fraction of trihydroxyl group chains per vinyl alcohol unit at a value of 65 to 98.0% by triad expression, preferably a value satisfying the formula: -1.5×Et+100>=mol fraction >=-Et+85 (Et is the content of ethylene).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a fiber sizing agent comprising a vinyl alcohol polymer. More specifically, the present invention relates to a fiber sizing agent having excellent biodegradability and good weaving properties.

[0002]

2. Description of the Related Art Conventionally, polyvinyl alcohol (hereinafter may be abbreviated as PVA) is most often used as a warp sizing agent for woven fabrics. It is washed away in the first step. In addition, wastewater containing PVA generated during desizing is usually treated with activated sludge, but its biodegradability is not sufficient, and it is difficult to comply with strict wastewater regulations every year. Also, PV fiber modified with olefin such as ethylene
A is also known (Japanese Patent Application Laid-Open Nos. 8-260355 and 9-31849), but this fiber sizing agent is still insufficient in biodegradability and weaving, although it is excellent.

[0003]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned drawbacks of the prior art, and provides a fiber sizing agent having excellent biodegradability and excellent weaving properties. With the goal.

[0004]

The object of the present invention is to provide an ethylene unit having a content of 2 to 19 mol%, a degree of polymerization of 200 to 2,000,
Degree of saponification 80.0 to 99.99 mol% and total content of carboxylic acid and lactone ring 0.020 to 0.40 mol%
This is achieved by providing a fiber sizing agent comprising a vinyl alcohol-based polymer.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS It is essential that the vinyl alcohol-based polymer of the present invention has an ethylene unit. The content of the ethylene unit is essential to be 2 to 19 mol%, preferably 2.5 to 17 mol%, and more preferably 3 to 19 mol%.
15 mol% is more preferable, and 3.5 to 13 mol% is particularly preferable. When the content of the ethylene unit is less than 2 mol%, the stability of the aqueous solution at low temperature and the degree of improvement in biodegradability are small. When the content of the ethylene unit is more than 19 mol%, the water solubility which is the most characteristic feature of PVA is reduced.

The content of ethylene units in the vinyl alcohol polymer of the present invention was determined by proton NMR of a polyvinyl ester containing ethylene units, which is a precursor of the vinyl alcohol polymer. That is, the obtained polyvinyl ester was sufficiently purified by reprecipitation with n-hexane / acetone three times or more, and then dried under reduced pressure at 80 ° C. for 3 days to prepare a polyvinyl ester for analysis. The polymer was dissolved in DMSO-D ₆ and measured at 80 ° C. using 500 MHz proton NMR (JEOL GX-500). Peaks derived from the main chain methine of the vinyl ester (4.7 to 5.2 ppm) and peaks derived from ethylene, the vinyl ester and the main chain methylene of the third component (0.
(8 to 1.6 ppm) to calculate the content of ethylene units.

The viscosity-average degree of polymerization (hereinafter abbreviated as degree of polymerization) of the vinyl alcohol polymer of the present invention is 200 to 30.
00, preferably 220 to 2500. Polymerization degree 2
If it is less than 00, the weaving property is not sufficient, and if it is more than 3000, the viscosity of the aqueous solution increases and the weaving property deteriorates.

The degree of polymerization (P) of a PVA polymer is determined according to JIS.
-Measured according to K6726. That is, it is obtained by the following formula from the intrinsic viscosity [η] (dl / g) measured in water at 30 ° C. after re-saponifying and purifying the PVA-based polymer. P = ([η] × 10 ³ /8.29) ^{(1 / 0.62)}

The degree of saponification of the vinyl alcohol polymer of the present invention is from 80 to 99.99 mol%, and from 84 to 99.9.
Mol% is preferable, 87 to 99.7 mol% is more preferable, and 90 to 99.5 mol% is particularly preferable. If the degree of saponification is less than 80 mol%, water solubility and biodegradability are not sufficient.

The total content of carboxylic acid and lactone ring in the vinyl alcohol polymer of the present invention is 0.020 to 0.4.
0 mol%, preferably 0.022 to 0.37 mol%, more preferably 0.024 to 0.33 mol%.
025 to 0.30 mol% is particularly preferred. The carboxylic acid in the present invention includes an alkali metal salt thereof, and examples of the alkali metal include potassium and sodium.
When the total content of the carboxylic acid and the lactone ring is less than 0.020 mol%, the biodegradability is not sufficient. On the other hand, when the total content of the carboxylic acid and the lactone ring exceeds 0.40 mol%, the biodegradability may decrease.

Further, it has been found that when the total content of carboxylic acid and lactone rings satisfies the following expression 3, the effect of the present invention is significantly increased.

[0012]

(Equation 3)

(Here, the content (unit: mol%) represents the total content of the carboxylic acid and the lactone ring, and P represents the viscosity average degree of polymerization of the vinyl alcohol polymer.)

A method for producing a vinyl alcohol-based polymer having a specific amount of ethylene units and having a carboxylic acid and a lactone ring includes a vinyl ester monomer such as vinyl acetate and an ability to form a carboxylic acid and a lactone ring. A method of saponifying a vinyl ester polymer obtained by copolymerization with a monomer having the same in an alcohol or dimethyl sulfoxide solution, the presence of a thiol compound containing a carboxylic acid such as mercaptoacetic acid or 3-mercaptopropionic acid Under the method of polymerizing a vinyl ester monomer and then saponifying it, when polymerizing a vinyl ester monomer such as vinyl acetate, the alkyl group of the vinyl ester monomer and the vinyl ester polymer A method of causing a chain transfer reaction to, saponifying after obtaining a hyperbranched vinyl ester polymer, A method in which a copolymer of a monomer having a oxy group and a vinyl ester monomer is reacted with a thiol compound having a carboxyl group, followed by saponification, a method by acetalization reaction between PVA and an aldehyde having a carboxyl group And the like.

The vinyl ester monomers include vinyl formate, vinyl acetate, vinyl propionate, vinyl valerate, vinyl caprate, vinyl laurate, vinyl stearate, vinyl benzoate, vinyl pivalate and vinyl versatate. Among these, vinyl acetate is preferred from the viewpoint of obtaining PVA. Monomers having the ability to form a carboxylic acid and a lactone ring of the present invention include fumaric acid, maleic acid, itaconic acid,
A monomer having a carboxyl group derived from maleic anhydride or itaconic anhydride, acrylic acid and a salt thereof,
Methyl acrylate, ethyl acrylate, acrylic acid n-
Propyl, acrylates such as i-propyl acrylate, methacrylic acid and salts thereof, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate,
Methacrylic esters such as i-propyl methacrylate, acrylamide, N-methylacrylamide, N-
Examples include acrylamide derivatives such as ethylacrylamide, and methacrylamide derivatives such as methacrylamide, N-methylmethacrylamide, and N-ethylmethacrylamide.

The total content of carboxylic acid and lactone ring of the vinyl alcohol polymer can be determined from the peak of proton NMR. After completely saponifying the vinyl alcohol-based polymer to a degree of saponification of 99.95 mol% or more, it was thoroughly washed with methanol and then dried at 90 ° C. under reduced pressure for 2 days to prepare a vinyl alcohol-based polymer for analysis. In the above case, to dissolve the polyvinyl alcohol for analysis created _{DMSO-D 6,} 500 MHz proton N
It measured at 60 degreeC using MR (JEOL GX-500). Acrylic acid, acrylic acid esters, acrylamide and acrylamide derivative monomers can be synthesized from methacrylic acid, methacrylic esters, methacrylamide and methacrylamide derivatives using the peak (2.0 ppm) derived from the main chain methine. The dimer has a peak derived from a methyl group directly connected to the main chain (0.6 to 1.1 ppm).
Was used to calculate the content by an ordinary method. Fumaric acid,
Maleic acid, itaconic acid, the monomer having a carboxyl group derived from maleic anhydride or itaconic anhydride and the like, added a few drops of lysis after trifluoroacetic acid analysis PVA that was created DMSO-D _6, 500 MHz proton N
It measured at 60 degreeC using MR (JEOLGX-500). For quantification, the content was calculated by an ordinary method using the methine peak of the lactone ring attributed to 4.6 to 5.2 ppm. In the cases of and, the content was calculated using the peak (2.8 ppm) derived from methylene bonded to the sulfur atom. In the case of, the prepared analytical PVA is
It was dissolved in D ₄ / D ₂ O = 2/8 and measured at 80 ° C. using 500 MHz proton NMR (JEOL GX-500). The peak derived from methylene of the terminal carboxylic acid or its alkali metal salt (Chemical Formulas 1 and 2 below) is 2.
2 ppm (integral value A) and 2.3 ppm (integral value B)
The peak derived from methylene of the terminal lactone ring (the following chemical formula 3) was 2.6 ppm (integral value C), and the peak derived from methine in the vinyl alcohol unit was 3.5 to 4.15 p.
pm (integral value D), and the contents of carboxylic acid and lactone rings are calculated by the following chemical formula (3). Here, △ indicates the amount of modification (mol%). Carboxylic acid and lactone ring content (mol%) = 50
× (A + B + C) × (100− △) / (100 × D)

[0017]

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[0018]

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[0019]

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In the case of (1), the prepared analysis PVA is
It was dissolved in O-D ₆ and proton NMR at 500 MHz (J
EOL GX-500) at 60 ° C. Peak 4.8 to 5.2 derived from methine in the acetal moiety
The content was calculated by a standard method using ppm (the following chemical formula 4).

[0021]

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As long as the effects of the present invention are not impaired,
It may contain a vinyl alcohol unit, ethylene, a vinyl ester unit, and a monomer unit other than the above-mentioned monomer capable of forming a carboxylic acid and lactone ring. Examples of such a unit include α-olefins such as propylene, 1-butene, isobutene, and 1-hexene;
Acrylamide derivatives such as acrylamide, N-methylacrylamide, N-ethylacrylamide, methacrylamide derivatives such as methacrylamide, N-methylmethacrylamide, N-ethylmethacrylamide, methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, i-propyl Vinyl ethers, vinyl ethers such as n-butyl vinyl ether, ethylene glycol vinyl ether, 1,3-propanediol vinyl ether, hydroxy group-containing vinyl ethers such as 1,4-butanediol vinyl ether, allyl acetate, propyl allyl ether, butyl allyl ether, Allyl ethers such as hexyl allyl ether; monomers having an oxyalkylene group; vinylsila such as vinyltrimethoxysilane Kind, isopropenyl acetate, 3
Buten-1-ol, 4-penten-1-ol, 5-
Hexen-1-ol, 7-octen-1-ol, 9
-Decene-1-ol, 3-methyl-3-butene-1-
Monomers having a sulfonic acid group derived from hydroxy group-containing α-olefins such as all, ethylenesulfonic acid, allylsulfonic acid, methallylsulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, etc .; vinyloxy Ethyltrimethylammonium chloride, vinyloxybutyltrimethylammonium chloride, vinyloxyethyldimethylamine, vinyloxymethyldiethylamine, N-acrylamidomethyltrimethylammonium chloride, 3- (N-methacrylamido) propyltrimethylammonium chloride, N-acrylamidoethyltrimethylammonium Chloride, N-acrylamidodimethylamine, allyltrimethylammonium chloride, methallyltrimethylammonium chloride, Ruariruamin include monomers having a cationic group derived from the allyl ethyl amine. The content of these monomers varies depending on the purpose and use of the monomers, but is usually 20 mol% or less, preferably 1 mol% or less.
0 mol% or less.

The vinyl alcohol-based polymer of the present invention may be a vinyl ester-based monomer such as vinyl acetate in the presence of a thiol compound such as 2-mercaptoethanol or n-dodecyl mercaptan, excluding the above-mentioned mercaptan having a carboxylic acid. May be terminally modified by copolymerizing with ethylene and saponifying it.

Examples of the method for copolymerizing the vinyl ester monomer with ethylene include known methods such as bulk polymerization, solution polymerization, suspension polymerization, and emulsion polymerization. Among them, a bulk polymerization method or a solution polymerization method in which polymerization is performed without a solvent or in a solvent such as an alcohol is usually employed.

The alcohol used as a solvent during the solution polymerization includes methyl alcohol, ethyl alcohol,
Lower alcohols such as propyl alcohol are exemplified.

The initiator used for the copolymerization includes α,
Azo-based initiator or peroxide-based initiator such as α'-azobisisobutyronitrile, 2,2'-azobis (2,4-dimethyl-valeronitrile), benzoyl peroxide, n-propylperoxydicarbonate Publicly known initiators such as agents. The polymerization temperature is not particularly limited,
A range from 0 ° C to 150 ° C is appropriate.

The vinyl alcohol polymer of the present invention has biodegradability, and is decomposed into water and carbon dioxide when treated with activated sludge or buried in soil. When the PVA is continuously treated with activated sludge, it is completely decomposed in two days. From the viewpoint of biodegradability, the vinyl alcohol-based polymer must be water-soluble or water-dispersible, and the 1,2-glycol bond content of the vinyl alcohol-based polymer is 1.2 to 2. 0 mol%, preferably 1.25 to 1.95 mol%, more preferably 1.3 to 1.9 mol%.
When the 1,2-glycol bond content of the vinyl alcohol-based polymer is less than 1.2 mol%, the biodegradability of the vinyl alcohol-based polymer described above becomes poor.

The 1,2-glycol bond content of the vinyl alcohol polymer can be controlled by the copolymerization temperature represented by ethylene carbonate and the polymerization temperature. The 1,2-glycol bond content of PVA is N
It can be determined from the MR peak. Saponification degree 99.
After saponification to 9 mol% or more, washing with methanol was carried out sufficiently, and then drying under reduced pressure at 90 ° C. for 2 days was performed for PVA, followed by DMS
A sample dissolved in O-D ₆ and a few drops of trifluoroacetic acid was added to the sample to obtain a 500 MHz proton NMR (JEOL GX-5).
00) at 80 ° C. The methine-derived peak of the vinyl alcohol unit is assigned to 3.2 to 4.0 ppm (integral value A), and the methine-derived peak of one of the 1,2-glycol bonds is assigned to 3.25 ppm (integral value B). The 1,2-glycol bond content can be calculated. Here △
Represents the ethylene modification amount (mol%). 1,2-glycol bond content (mol%) = B (100
− △) / A

In the present invention, the central hydroxyl group of three hydroxyl groups in triad notation with respect to a vinyl alcohol unit is defined as 500 M of PVA in a DMSO-D ₆ solution.
Hz proton NMR (JEOL GX-500) device,
The peak (I) reflecting the tacticity of the triad of the hydroxyl proton measured at 65 ° C. is meant. Peak (I) is represented by the sum of isotacticity (4.54 ppm), heterotacticity (4.36 ppm) and syndiotacticity (4.13 ppm) of the triad representation of the hydroxyl group of PVA. The peak (II) derived from the hydroxyl group in the vinyl alcohol unit of the formula (1) has a chemical shift from 4.05 ppm to 4.70 p.
pm, the mole fraction of trihydroxyl center hydroxyl groups in the triad representation with respect to the vinyl alcohol unit of the present invention is 100 × (I) / (II)
It is represented by

In the present invention, the biodegradability of the vinyl alcohol-based polymer, the film strength, and the like can be controlled by controlling the amount of the central hydroxyl group in the three hydroxyl groups. This is presumably because the central hydroxyl group of the three-chain hydroxyl group in triad notation is rich in crystallinity, thereby exhibiting the characteristics of the vinyl alcohol polymer.

The content of the 3-hydroxyl center hydroxyl group of the vinyl alcohol polymer of the present invention in the triad representation is 65 to 98.0 mol%, and 70 to 97.5 mol%.
Is preferable, and 72 to 97 mol% is more preferable, and 74 to 97 mol% is preferable.
96 mol% is more preferable, and 75 to 95 mol% is particularly preferable.

Further, when the vinyl alcohol polymer of the present invention has a mole fraction of three hydroxyl groups in the center of triads with respect to a vinyl alcohol unit satisfying the following formula 4, the effect of the present invention is remarkably high. I found out.

[0033]

(Equation 4)

Here, the mole fraction (unit: mole%) represents the mole fraction of the center hydroxyl group of three hydroxyl groups in triad notation with respect to the vinyl alcohol unit, and Et represents the ethylene content (containing the vinyl alcohol polymer). (Unit: mol%). ｝

In the vinyl alcohol polymer composition containing ethylene of the present invention, water solubility and weavability can be further improved by having an alkali metal.
The content ratio of the alkali metal (B) to 100 parts by weight of the vinyl alcohol polymer (A) is as follows.
Is 0.0003 to 1 part by weight in terms of sodium,
0.0003 to 0.8 part by weight is preferable, and 0.0005 to 0.0005 part by weight.
-0.6 parts by weight, more preferably 0.0005-0.5 parts by weight.
Part by weight is particularly preferred. Examples of the alkali metal include potassium, sodium, etc., which are mainly salts of lower fatty acids such as acetic acid and propionic acid, salts of carboxylic acids of PVA containing a specific amount of the carboxylic acid of the present invention, and copolymer monomers. It may be present as a salt of sulfonic acid contained in, or even in an additive.

In the present invention, the method of incorporating a specific amount of the alkali metal (B) into the vinyl alcohol-based polymer is not particularly limited, and once the vinyl alcohol-based polymer is obtained, the alkali metal-containing compound is added. Method,
When saponifying a vinyl ester polymer in a solvent, an alkali metal containing an alkali metal is used as a saponification catalyst to blend the alkali metal into the vinyl alcohol-based polymer, and the saponified vinyl alcohol-based polymer is obtained. By washing the polymer with a washing solution,
A method of controlling the alkali metal contained in the vinyl alcohol-based polymer may be mentioned, but the latter is more preferable. The content of the alkali metal can be determined by an atomic absorption method.

The method for producing the specific ethylene-containing vinyl alcohol polymer of the present invention is as follows: a vinyl ester polymer obtained by copolymerizing ethylene and the above-mentioned vinyl ester monomer is converted into an alcohol or dimethyl alcohol. Known methods such as a method of saponification in a sulfoxide solution can be used.

Examples of the alkaline substance used as the saponification catalyst include potassium hydroxide or sodium hydroxide. The molar ratio of the alkaline substance used in the saponification catalyst is preferably from 0.004 to 0.5, particularly preferably from 0.005 to 0.05, based on the vinyl acetate unit. The saponification catalyst may be added all at once in the early stage of the saponification reaction, or may be additionally added during the saponification reaction. Examples of the solvent for the saponification reaction include methanol, methyl acetate, dimethyl sulfoxide, dimethylformamide and the like. Of these solvents, methanol is preferred, and the water content is 0.1%.
Methanol controlled at 001 to 1% by weight is more preferable, methanol controlled at a water content of 0.003 to 0.9% by weight is more preferable, and methanol controlled at a water content of 0.005 to 0.8% by weight is preferable. Particularly preferred. The temperature of the saponification reaction is preferably 5 to 80 ° C, more preferably 20 to 70 ° C.
Is more preferred. The saponification time is preferably 5 minutes to 10 hours, more preferably 10 minutes to 5 hours. Known methods such as a batch method and a continuous method can be applied as the saponification method.

As the cleaning liquid, methanol, acetone,
Examples thereof include methyl acetate, acetate, hexane, and water. Among them, methanol, methyl acetate, and water alone or a mixed solution are more preferable. The amount of the cleaning liquid is set so as to satisfy the content ratio of the alkali metal (B), but usually, 30 to 10 parts by weight with respect to 100 parts by weight of PVA.
000 parts by weight are preferred, and 50 to 3000 parts by weight are more preferred. The washing temperature is preferably 5 to 80C,
20-70 degreeC is more preferable. The washing time is preferably from 20 minutes to 10 hours, more preferably from 1 hour to 6 hours. Known methods such as a batch method and an AC cleaning method can be applied as the cleaning method.

The specific ethylene modification amount obtained in the present invention,
Degree of polymerization, degree of saponification, carboxylic acid and lactone ring amount,
A fiber sizing agent composed of a vinyl alcohol polymer having a 1,2-glycol bond amount and a hydroxyl group is extremely useful as a warp sizing agent. The resin concentration of the size liquid composed of the aqueous solution of the size agent is preferably about 3 to 15%.
In the case of spun yarn, since there are many combinations of synthetic fibers and natural fibers, it is necessary to prepare a sizing solution suitable for the warp.In the case of filament, the main purpose is to bundle by bonding between single fibers. It is necessary to prepare a paste liquid having high viscosity and high adhesiveness.
The amount of the glue adhered to the fiber is arbitrarily selected depending on the type of the woven fabric, the loom to be used, the sizing machine, and the like.
About 5% is preferable.

The fiber sizing agent of the present invention includes ordinary PVA, starch, modified starch (modified starch), acrylic sizing agent, water-soluble cellulosic compound (hydroxyl cellulose, carboxyl group) as long as the object of the present invention is not impaired. Methylcellulose, etc.), oils, and other auxiliaries (such as antifoaming agents, fungicides, antistatic agents, anionic surfactants, nonionic surfactants, and cationic surfactants) can also be used in combination.

[0042]

The present invention will be described in more detail with reference to the following Examples and Comparative Examples. In the following Examples and Comparative Examples, “parts” and “%” mean on a weight basis unless otherwise specified. In addition, the obtained ethylene-modified PVA was evaluated for analysis, water solubility, biodegradability, and weavability in the following manner.

[Method of Analyzing Ethylene-Modified PVA] PVA
The analysis method of JIS-K6726 is used unless otherwise specified.
Followed. The modified amount of ethylene in the present invention is a modified polyvinyl ester, and the total content of carboxylic acid and lactone ring, the amount of 1,2-glycol bond and the content of three hydroxyl groups are 500 MHz protons using modified PVA. It was determined as described above from measurement with an NMR (JEOL GX-500) apparatus. The melting point of the modified PVA of the present invention is determined by using a DSC (Mettler, TA3000) in nitrogen at a rate of 10 ° C./min. The temperature at the peak top of the endothermic peak indicating the melting point of PVA when the temperature was raised to 250 ° C. was examined. The content of the alkali metal was determined by an atomic absorption method.

[Water solubility of ethylene-modified PVA] A predetermined amount of PVA was dispersed in distilled water so that the dissolution concentration was 10%, and the mixture was heated and stirred at a temperature of 95 ° C. for 3 hours.
A aqueous solution was prepared. Subsequently, it cooled to 20 degreeC and evaluated visually. The results are indicated by the following symbols.

5: completely dissolved in water, and the aqueous solution is colorless and transparent. 4: Dissolves completely in water, but the aqueous solution is cloudy. 3: Almost soluble in water, but partially insoluble. 2: There are considerable insolubles. 1: Does not dissolve at all.

[Ethylene-modified PVA biodegradability] The biodegradability of ethylene-modified PVA having a carboxylic acid and a lactone ring was evaluated using a continuous wastewater treatment tester comprising a 5 L aeration tank and a 2 L precipitation tank. After dissolving PVA in water, PVA, glucose, L-glutamic acid, ammonium chloride, potassium chloride, potassium disodium phosphate,
700, 360, 180, 12 of dipotassium diphosphate potassium, calcium chloride, iron sulfate and magnesium sulfate
0, 8.4, 300, 300, 6.7, 1.5, 0.7
Dissolved in water at each concentration (mg / l) and pH 7 with caustic soda.
, And sterilized and used for the medium. Sludge from sewage treatment plant is used, and initial sludge concentration is 4400ppm
And The supply rate of the culture medium to the aeration tank was 5 L / day, the amount of aeration was 2 L / day, and the liquid overflowing from the aeration tank was transferred to the sedimentation tank, after which the precipitate was separated and then fed back to the aeration tank as sludge. After a treatment test at a treatment temperature of 30 ° C. for three consecutive days, suspended sludge was collected from the center of the aeration tank with a pipette. Then, after centrifugation, the PVA concentration (ppm) in the supernatant was determined by the iodine method.
The biodegradability (%) of VA was determined.

[Weaving property of ethylene-modified PVA] An ethylene-modified PVA concentration of 7% and an oil (Warp set 100;
A paste consisting of an aqueous solution having a concentration of 0.7% (manufactured by Takemoto Yushi Co., Ltd.) was prepared and woven under the following conditions. (1) Fabric warp: Polyester (65%) / cotton (35%) blend 4
5/1 Comb Weft: Same as above Tissue: Plain weaving loom: Air jet loom manufactured by Tsuda Koma Co. (3) Gluing Gluing machine: 2-box type made by Tsuda Koma Co., Ltd. Gluing temperature: 94 ° C. Yard / minute Drying temperature: 105-125 ° C (4) Weaving properties were evaluated according to the following criteria. Average weaving efficiency: ○ Greater than 93% of average weaving efficiency △ Average weaving efficiency of 85 to 93% × Less than 85% of average weaving efficiency Thread breakage: ○ Less than 0.4 warp breaks / hour △ 0.4 to 1 warp breakage / Hour × greater than 1 warp break / hour

Example 1 [Production of ethylene-modified PVA] Vinyl acetate 107.2 k was placed in a 250-L pressure reactor equipped with a stirrer, nitrogen inlet, ethylene inlet, initiator addition port and delay solution addition port.
g, methanol 42.8 kg and maleic anhydride 1
After charging 5.6 g, the temperature was raised to 60 ° C., and the inside of the system was replaced with nitrogen by bubbling nitrogen for 30 minutes. Then, ethylene was introduced and charged so that the reaction tank pressure became 5.9 kg / cm ² . A 2.8 g / L solution of 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile) (AMV) dissolved in methanol was prepared as an initiator, and nitrogen was replaced by bubbling with nitrogen gas. did. A 5% concentration solution of maleic anhydride dissolved in methanol was prepared as a delay solution, and nitrogen replacement was performed by bubbling with nitrogen gas. After adjusting the inside temperature of the polymerization tank to 60 ° C., 204 ml of the initiator solution was injected to start polymerization. During the polymerization, ethylene was introduced to raise the reaction vessel pressure to 5.
9 kg / cm ² , the polymerization temperature was maintained at 60 ° C., AMV was used at 640 ml / hr using the above-mentioned initiator solution, and maleic anhydride was used using the above-mentioned delay solution to polymerize vinyl acetate and maleic anhydride in the polymerization system. Polymerization was carried out by continuous addition while keeping the acid ratio constant. After 4 hours, when the polymerization rate reached 30%, the polymerization was stopped by cooling.
At this point, the total amount of the maleic anhydride delay solution added by delay was 1400 ml. After the reaction vessel was opened to remove ethylene, nitrogen gas was bubbled through to completely remove ethylene. Next, unreacted vinyl acetate monomer was removed under reduced pressure to obtain a methanol solution of polyvinyl acetate. To the obtained polyvinyl acetate solution, 333 g of a methanol solution of polyvinyl acetate adjusted to a concentration of 30% by adding methanol (polyvinyl acetate 1 in the solution).
(00g), an alkali solution (10% NaOH solution in methanol) having an alkali solution of 46.5 g (molar ratio [MR] 0.10 to vinyl acetate unit in polyvinyl acetate) was added to perform saponification. About 1 minute after the addition of the alkali, the gelled system was pulverized with a pulverizer and left at 40 ° C. for 1 hour to progress the saponification. Then, 1000 g of methyl acetate was added to neutralize the remaining alkali. After confirming the completion of neutralization using a phenolphthalein indicator, 1000 g of methanol was added to the white solid PVA obtained by filtration, and the mixture was added at room temperature for 3 hours.
It was left to wash for a period of time. After repeating the above washing operation three times,
The PVA obtained by centrifugal drainage was left in a dryer at 70 ° C. for 2 days to obtain a dried PVA (PVA-1).

[Analysis of Ethylene-Modified PVA] Ethylene-modified PVA having carboxylic acid and lactone rings obtained
Was 98.5 mol%. The modified PV
After incineration of A, the content of sodium measured by atomic absorption spectrophotometry using a substance dissolved in acid was modified PV
The amount was 0.36 parts by weight based on 100 parts by weight of A. Further, a methanol solution of polyvinyl acetate obtained by removing unreacted vinyl acetate monomer after polymerization was precipitated in n-hexane and reprecipitated by dissolving with acetone three times.
Drying under reduced pressure at 3 ° C. for 3 days gave purified polyvinyl acetate. The polyvinyl acetate was dissolved in DMSO-D _6, 50
The content of ethylene units was 7 mol% as measured at 80 ° C. using 0 MHz proton NMR (JEOLX-500). After saponifying the above methanol solution of polyvinyl acetate at an alkali molar ratio of 0.5, the pulverized product was allowed to stand at 60 ° C. for 5 hours to progress saponification, and then methanol soxhlet was carried out for 3 days.
The resultant was dried under reduced pressure at 0 ° C. for 3 days to obtain a purified carboxylic acid and an ethylene-modified PVA having a lactone ring. The P
When the average degree of polymerization of VA was measured according to a conventional method JIS K6726, it was 1000. The purified PVA had a carboxylic acid and lactone ring content, a 1,2-glycol bond amount and a hydroxyl group content of three hydroxyl groups of 500.
It was 0.246 mol%, 1.61 mol%, and 87%, respectively, as determined from the measurement with a MHz proton NMR (JEOL GX-500) apparatus as described above. Further, a 5% aqueous solution of the purified modified PVA was adjusted to prepare a cast film having a thickness of 10 μm.
After drying the film under reduced pressure at 80 ° C. for 1 day, D
The melting point of PVA was 210 ° C. when the melting point of PVA was measured using SC (Mettler, TA3000) by the method described above.

[Water solubility, biodegradability and weaving property of ethylene-modified PVA] The ethylene-modified PVA (P
Using VA-1) to evaluate the water solubility by the above-mentioned method, it was completely dissolved in distilled water and the aqueous solution was colorless and transparent. Further, the biodegradability and the weaving property were measured according to the above-mentioned formula. Table 13 shows the results.

Examples 2 to 5, 8 to 11, 12 and 16
１７17 A vinyl ester polymer was synthesized in exactly the same manner as in Example 1 except that the conditions shown in Tables 1 and 2 were changed. Subsequently, the PVA was produced in the same manner as in Example 1 except that the vinyl ester polymer was changed to the conditions shown in Tables 3 and 4.
An A-based polymer was synthesized. Ethylene content, polymerization degree, saponification degree, carboxylic acid and lactone ring content, 1,2-glycol bond amount of the obtained PVA-based polymer, amount of central hydroxyl group of three chains of hydroxyl groups in triad notation with respect to vinyl alcohol unit, and Tables 5 and 6 show the content of alkali metal in terms of sodium based on 100 parts by weight of the PVA-based polymer. Tables 13 and 14 show the water solubility, biodegradability and weaving properties of the obtained PVA-based polymer.

Comparative Examples 1-4, 6-11 and 13-15 The pressure during the polymerization was changed (PVA containing no ethylene)
When synthesizing a system polymer, polymerization was carried out in a state of nitrogen sealing. ), Etc., except that the conditions shown in Tables 7 and 8 were changed, to synthesize a vinyl ester polymer in exactly the same manner as in Example 1. Subsequently, the vinyl ester-based polymer was added in Table 9
A PVA-based polymer was synthesized in exactly the same manner as in Example 1, except that the conditions shown in Table 10 were changed. Obtained PV
Ethylene content, degree of polymerization, degree of saponification, carboxylic acid and lactone ring content, 1,2-glycol bond amount of A-based polymer, amount of central hydroxyl group of 3 chains of hydroxyl groups in triad notation with respect to vinyl alcohol unit, and PVA
Tables 11 and 12 show the content of alkali metal in terms of sodium based on 100 parts by weight of the polymer. Tables 15 and 16 show the water solubility, biodegradability and ゛ weavability of the obtained PVA-based polymer.

As shown in Tables 13 to 16, in the evaluation of the water solubility, biodegradability and weavability of PVA, only those having the physical properties in the predetermined range of the present invention showed good results. In each case, any of the comparative examples had poor water solubility, biodegradability or weaving property.

Example 6 and Comparative Example 5 In Example 6, 76.6 kg of vinyl acetate, 73.3 kg of methanol and 73.3 kg of methanol were placed in a 250-L pressure reactor equipped with a stirrer, a nitrogen inlet, an ethylene inlet, and an initiator inlet. 217 g of allyl glycidyl ether was charged and the system was replaced with nitrogen in the same manner as in Example 1. Then the reactor pressure,
A vinyl ester polymer containing allyl glycidyl ether was polymerized in exactly the same manner as in Example 1 except that the conditions shown in Table 1 were changed, such as the amount of AMV and allyl glycidyl ether as a comonomer were not continuously added. After 3 hours, when the polymerization rate reached 20%, the polymerization was stopped by cooling, the reaction vessel was opened to remove ethylene, and then nitrogen gas was bubbled to completely remove ethylene. Next, unreacted vinyl acetate monomer was removed under reduced pressure to obtain a methanol solution of polyvinyl acetate. 0.54 g of 3-mercaptopropionic acid was added to 286 g of methanol solution of polyvinyl acetate (100 g of polyvinyl acetate in the solution) adjusted to have a concentration of 35% by adding methanol to the obtained polyvinyl acetate solution. After adding 0.1 g of sodium acetate and stirring at 50 ° C. for 2 hours, saponification was performed by adding 46 g of an alkaline solution (a 10% methanol solution of NaOH). After about 1 minute from the addition of the alkali, the gelled system was pulverized with a pulverizer, left at 40 ° C. for 1 hour to progress the saponification, and 1000 g of a 1% methanol solution of acetic acid was added to remove the remaining alkali. Neutralized. After confirming the completion of the neutralization using a phenolphthalein indicator, 1000 g of methanol was added to PVA as a white solid obtained by filtration, and washed by standing at room temperature for 3 hours. After repeating the above washing operation three times, the PVA obtained by centrifugal dewatering was placed in a dryer at 70 ° C.
For 2 days to obtain an ethylene-modified PVA having a carboxylic acid (PVA-6). The ethylene-modified PV
Table 5 and Table 13 show the analysis results and evaluation results of A. Comparative Example 5 was prepared in the same manner as in Example 6 except that the conditions shown in Tables 7 and 9 were changed, for example, polymerization under ethylene pressure was carried out under a nitrogen seal.
VA (PVA-34) was obtained. Table 11 and Table 15 show the analysis results and evaluation results of the PVA.

Example 7 In Example 7, 4-oxo-butane was prepared by adding concentrated hydrochloric acid to a 10% aqueous solution obtained by dissolving 100 g of PVA-2 in distilled water to adjust the pH of the aqueous solution to 1. Acid 0.52
g and stirred at 50 ° C. for 2 hours.
H solution to neutralize the pH of the solution to 7.
The PVA precipitated by throwing into OH was separated by filtration and subjected to Soxhlet extraction (MeOH) for 3 days, and then left in a dryer at 70 ° C. for 2 days to dry ethylene-modified PVA (PVA-7) having a carboxylic acid. Obtained. The analysis results of each PVA are shown in Tables 5 and 11, and the evaluation results are shown in Tables 13 and 15, respectively.

As shown in Table 5, when the reaction product of polyvinyl acetate having an epoxy group and thiol having a carboxylic acid was saponified as in Example 6, or an aldehyde compound having a carboxylic acid in PVA was acetalized. It can be seen that the carboxylic acid and lactone rings can be introduced into PVA without any problem even when the addition reaction is carried out. Further, as shown in Example 6 and Example 7 in Table 13, the carboxylic acid and lactone rings introduced by using such a method have functions completely different from those introduced by a method such as copolymerization. I understand.

Example 16 and Comparative Example 12 The comonomer, ethyl vinyl ether or vinyl trimethoxysilane, was added only during the polymerization preparation operation, and was not added continuously during the polymerization, and Tables 2, 4, 8, and 10 show that: Except that the conditions were changed, the terpolymer modified PVA (PVA-15, PVA
A-41) was obtained. Table 6 shows the analysis results of each PVA.
Table 12 and Table 12 show the evaluation results, respectively.

Examples 13 and 14 and Comparative Examples 16 and 17 Examples 13 and 14 differ from Example 2 in that PVA-2 was used.
In the same manner as in Example 2 except that the PVA paste obtained by polymerization during the synthesis of
A (PVA-13, PVA-14) was obtained. Comparative Example 16
And 17 are P under the conditions shown in Tables 8 and 10.
VA-45 and PVA-46 were obtained. Each PV
Table 6 and Table 12 show the analysis results of A, and Table 14 shows the evaluation results.
And Table 16 respectively.

[0059]

[Table 1]

[0060]

[Table 2]

[0061]

[Table 3]

[0062]

[Table 4]

[0063]

[Table 5]

[0064]

[Table 6]

[0065]

[Table 7]

[0066]

[Table 8]

[0067]

[Table 9]

[0068]

[Table 10]

[0069]

[Table 11]

[0070]

[Table 12]

[0071]

[Table 13]

[0072]

[Table 14]

[0073]

[Table 15]

[0074]

[Table 16]

[0075]

The fiber sizing agent of the present invention has excellent biodegradability,
And the weavability is good.

Claims (5)

[Claims] 1. An ethylene unit content of 2 to 19 mol%,
Degree of polymerization 200-3000, degree of saponification 80.0-99.9
A fiber sizing agent comprising a vinyl alcohol polymer having 9 mol% and a total content of carboxylic acid and lactone ring of 0.020 to 0.40 mol%. 2. The fiber paste according to claim 1, wherein the total content of the carboxylic acid and the lactone ring of the vinyl alcohol polymer satisfies the following expression (1). (Equation 1) ｛Here, the content (unit: mol%) represents the total content of the carboxylic acid and the lactone ring, and P represents the viscosity average degree of polymerization of the vinyl alcohol polymer. ｝ 3. A vinyl alcohol polymer having a 1,2-glycol bond content of 1.2 to 2.0 mol%, and a triad-noted triad notation of a 3-hydroxyl-based central hydroxyl group mole fraction of 65 to 98 based on vinyl alcohol units. 0.0 mol%
The fiber paste according to claim 1 or 2, wherein 4. The fiber sizing agent according to claim 3, wherein the molar fraction of three hydroxyl groups at the center of the hydroxyl group in the vinyl alcohol polymer triad expression satisfies the following expression (2). (Equation 2) ｛Here, the mole fraction (unit: mole%) represents the mole fraction of the central hydroxyl group of three hydroxyl groups in triad notation with respect to the vinyl alcohol unit, and Et is the ethylene content (unit: mole) contained in the vinyl alcohol polymer. %). ｝ 5. The vinyl alcohol-based polymer (A) according to any one of claims 1 to 4, wherein
Fiber sizing agent containing 0.0003 to 1 part by weight of alkali metal (B) in terms of sodium.